1. Field of the Invention
The present invention relates to an image forming optical system, imaging apparatus, profile measuring apparatus, structure manufacturing system and structure manufacturing method.
2. Description of the Related Art
A tilted-lens image forming optical system is used in a projector, an imaging apparatus, a focusing apparatus provided with an imaging apparatus, a profile measuring apparatus provided with an imaging apparatus, etc. (see, for example, U.S. Pat. No. 5,090,811). For example, a profile measuring apparatus using the optical cutting method, etc. takes an image of an object onto which an illumination light is irradiated, and obtains an information regarding the profile of the object based on the imaging result. In the profile measuring apparatus, a direction in which the object irradiated with the illumination light is observed (imaged) is set to define an acute angle with respect to the light irradiation direction from which the illumination light is irradiated onto the object. Accordingly, an image forming optical system in the profile measuring apparatus is constructed, for example, as a tilted-lens image forming optical system which satisfies the Scheimpflug condition.